Limb and cardiovascular event risk in type 1 and 2 diabetic patients with peripheral artery disease.

Background: Peripheral artery disease (PAD) is a risk factor for adverse limb events (LE) and cardiovascular events (CVE) that coexists with type 1 (T1) and 2 (T2) diabetes mellitus (DM). Little is known about comparative risk of LE and CVE in T1/T2 DM patients with PAD. Patients and methods: We queried our database of 40,144 patients ≥18 years old who underwent ankle brachial index (ABI) measurement from 01/1996-02/2020. We isolated T1/T2 DM patients with PAD diagnosed by ankle brachial index (ABI; low [<1.0] or elevated [>1.4]) and retrieved demographics including glycated hemoglobin (HbA1c). Primary outcomes were LE (critical limb ischemia/vascular amputation) and CVE (myocardial infarction/ischemic stroke). All-cause mortality was a secondary outcome. Multivariable Cox proportional regression yielded hazard ratios (HR) with 95% confidence intervals (CI) after adjusting for pertinent risk factors including age, hypertension, hyperlipidemia, smoking, and HbA1c. Results: Our study found 10,156 patients with PAD and DM (34% T1DM, 66% T2DM) with median follow-up time 34 mo (IQR 85 mo). T1DM patients were younger than T2DM (mean age 67 vs. 70 years), with higher median HbA1c (7.7 [IQR 1.9] vs. 6.7% [IQR 1.6]), and more prevalent hypertension, hyperlipidemia, CAD, and CKD. Antiplatelet and statin use was equivocal. Elevated ABI was more common in T1DM (47 vs. 28%). LE occurred in 23% and CVE in 12% patients. LE risk was higher in T1 than T2 DM patients (HR 1.58 [95% CI 1.44, 1.73], p<0.0001), but CVE and all-cause mortality were equivocal. These observations were preserved across ABI and HbA1c subgroup analyses. Conclusions: PAD patients with T1DM had a higher LE risk than those with T2DM, even after adjustment for glycemic control and pertinent risk factors, but CVE risk and all-cause mortality were equivocal. These data suggest a potential role for more intensive LE risk modification in PAD patients with T1DM, but further investigation is needed.

Safety and mortality outcomes for direct oral anticoagulants in renal transplant recipients.

PURPOSE: Direct oral anticoagulants (DOACs) are increasingly used in renal transplant recipients (RTR), but relatively understudied in this population. We assess the safety of post-transplant anticoagulation with DOACs compared to warfarin. METHODS: We conducted a retrospective study of RTRs at the Mayo Clinic sites (2011-present) that were anticoagulated for greater than 3 months excluding the 1st month post-transplant. The main safety outcomes were bleeding and all-cause mortality. Concomitant antiplatelet and interacting drugs were noted. DOAC dose adjustment was assessed according to common US prescribing practices, guidelines, and/or FDA labeling. RESULTS: The median follow-up was longer for RTRs on warfarin (1098 days [IQR 521, 1517]) than DOACs (449 days [IQR 338, 942]). Largely, there were no differences in baseline characteristics and comorbidities between RTRs on DOACs (n = 208; apixaban 91.3%, rivaroxaban 8.7%) versus warfarin (n = 320). There was no difference in post-transplant use of antiplatelets, immunosuppressants, most antifungals assessed, or amiodarone. There was no significant difference in incident major bleeding (8.4 vs. 5.3%, p = 0.89), GI bleeding (4.4% vs. 1.9%, p = 0.98), or intra-cranial hemorrhage (1.9% vs. 1.4%, p = 0.85) between warfarin and DOAC. There was no significant difference in mortality in the warfarin group compared to DOACs when adjusted for follow-up time (22.2% vs. 10.1%, p = 0.21). Rates of post-transplant venous thromboembolism, atrial fibrillation or stroke were similar between the two groups. 32% (n = 67) of patients on DOACs were dose reduced, where 51% of those reductions were warranted. 7% of patients that were not dose reduced should have been. CONCLUSIONS: DOACs did not have inferior bleeding or mortality outcomes compared to warfarin in RTRs. There was greater use of warfarin compared to DOACs and a high rate of improper DOAC dose reduction.

Peripheral artery disease and the risk of venous thromboembolism.

Background: Peripheral artery disease (PAD) impacts 3-12% of patients worldwide and is characterized by endothelial dysfunction and inflammatory pathways which are also common to venous thromboembolism (VTE), but there is a paucity of evidence regarding VTE risk in PAD patients. We investigated whether PAD is an independent risk factor for VTE. Patients and methods: We reviewed medical records of patients undergoing ABI studies at Mayo Clinic from 01/1996-02/2020. We classified patients by ABI (low [<1.0], normal [1.0-1.4], or elevated [>1.4]), as well as by specific low ABI subgroup: severely reduced (ABI: 0.00-0.39), moderately reduced (0.40-0.69), mildly reduced (0.70-0.90), and borderline reduced (0.91-0.99). The primary outcome was incident VTE event (acute lower extremity deep vein thrombosis or pulmonary embolism) after ABI measurement. Multivariable Cox proportional regression was used to calculate hazard ratios (HR) with 95% confidence intervals (CI) after adjusting for age, sex, active smoking, cancer, previous VTE, thrombophilia, anticoagulation, and revascularization. Results: 39,834 unique patients (mean age 66.3±14.3 years, median follow-up 34 months) were identified. 2,305 VTE events occurred in patients without PAD (13.0%), 2,218 in low ABI patients (13.0%), and 751 in elevated ABI patients (14.8%). After risk factor adjustment, VTE risk was modestly increased for PAD overall (HR: 1.12, 95% CI [1.06, 1.18]), including low ABI (HR: 1.11, 95% CI [1.04, 1.18]) and elevated ABI groups (HR: 1.15, 95% CI [1.04, 1.26]), compared to patients without PAD. The greatest VTE risk was in severely low ABI patients (HR: 1.46, 95% CI [1.31, 1.64]). Conclusions: In a large longitudinal cohort, we present strong clinical evidence of PAD, with low and elevated ABI, as an independent VTE risk factor, with the highest risk seen in patients with severely low ABI. Continued research is required to further investigate this relationship and its intersection with functional performance status to optimize VTE risk reduction or anticoagulation strategies in the PAD population.

Patient Age at Diagnosis of Peripheral Artery Disease and Its Impact on Cardiovascular and Limb Outcomes.

Peripheral artery disease (PAD) prevalence increases with age, but the relation between age at PAD diagnosis and outcomes is unclear. We investigated the cardiovascular and limb outcomes of patients diagnosed with PAD at different ages. We studied patients with PAD aged ≥18 years who were diagnosed between 1996 and 2020 at Mayo Clinic. Patients were grouped by diagnosis age (<50, 50 to 59, 60 to 69, ≥70 years) and ankle brachial index (ABI): low ABI (<1.0) or elevated ABI (>1.4). Primary outcomes were cardiovascular events (CVEs; myocardial infarction or ischemic stroke) and limb events (LEs; critical limb ischemia or amputation). Competing risk analysis was performed to calculate adjusted hazard ratios. The cohort included 22,073 patients with PAD (low ABI: 77.1%; elevated ABI: 22.9%). CVEs were observed in 8.2% of patients and LEs in 15.6%. The highest CVE risk was observed in patients diagnosed with PAD before age 50 (compared with patients diagnosed after age 70; hazard ratio 2.33 [95% confidence interval 1.95 to 2.78]). CVE risk decreased with older age at diagnosis. Although younger groups demonstrated higher LE risk, there was no clear association with diagnosis age. These patterns of risk were seen both in low and elevated ABI subgroups but in greater magnitude with elevated ABI. Younger patients diagnosed with PAD face increased risk of myocardial infarction and ischemic stroke compared with patients diagnosed at an older age. CVE risk notably exceeds LE risk. In conclusion, younger age at PAD diagnosis may be an important risk factor, which warrants more aggressive interventions focused on CVE prevention.

Lower Extremity Arterial Disease as a Predictor of Incident Atrial Fibrillation and Cardiovascular Events.

OBJECTIVE: To evaluate the relationship between peripheral arterial disease (PAD) and incident atrial fibrillation (AF) and its clinical and pathophysiologic implications on ischemic stroke and all-cause mortality. PATIENTS AND METHODS: We identified all adult patients in the Mayo Clinic Health System without a previous diagnosis of AF undergoing ankle-brachial index (ABI) testing for any indication from January 1, 1996, to June 30, 2018. Retrospective extraction of ABI data and baseline echocardiographic data was performed. The primary outcome of interest was incident AF. The secondary outcomes of interest were incident ischemic stroke and all-cause mortality. RESULTS: A total of 33,734 patients were included in the study. After adjusting for demographic and comorbidity variables, compared with patients who had normal ABI (1.0 to 1.39), there was an increased risk of incident AF in patients with low ABI (<1.0) (adjusted hazard ratio, 1.14; 95% CI, 1.06 to 1.22) and elevated ABI (≥1.4) (adjusted hazard ratio, 1.18; 95% CI, 1.06 to 1.31). The risk was greater in patients with increasing severity of PAD. Patients with abnormal ABIs had an increased risk of ischemic stroke and all-cause mortality. We found that patients with PAD and incident AF have certain baseline echocardiographic abnormalities. CONCLUSION: In this large cohort of ambulatory patients undergoing ABI measurement, patients with PAD were at increased risk for incident AF, ischemic stroke, and mortality. In these high-risk patients with abnormal ABI, particularly severe PAD and cardiac structural abnormalities, routine monitoring for AF and management of cardiovascular risk factors may be warranted.

Abnormal vascular physiology in the lower extremities as a risk factor for ischemic stroke and mortality.

CONTEXT: Peripheral artery disease (PAD) is highly prevalent in the general population, affecting up to 25% of patients 55 years of age or older. There is a known association with acute ischemic stroke, but limited large cohort studies exist pertaining to the relationship between PAD severity and incident ischemic stroke. OBJECTIVES: To evaluate the risk of incident ischemic stroke and mortality along the spectrum of low and elevated ankle brachial index (ABI) measurement. METHODS: We performed a retrospective extraction of ABI data of all adult patients who underwent lower extremity physiology study for any indication from January 1, 1996 to June 30, 2018 in the Mayo Clinic health system. PAD was categorized into severe, moderate, mild, and borderline based on ABI measurements and poorly compressible arteries (PCA). These were compared with normal ABI measurements. Associations of PAD/PCA with new ischemic stroke events and all cause mortality were analyzed. Hazard ratios (HR) were calculated using multivariable Cox proportional regression with 95% confidence intervals. RESULTS: A total of 39,834 unique patients were included with a median follow up duration of 4.59 years. All abnormal ABI groups, except borderline PAD, were associated with increased risk of incident ischemic stroke after multivariate regression compared to normal ABI. A severity-dependent association was observed between PAD and ischemic stroke with moderate (HR, 1.22 [95% CI, 1.10-1.35]) and severe (HR, 1.19 [95% CI, 1.02-1.40]) categories conferring similar risk in comparison to normal ABI. Patients with PCA carried the greatest ischemic stroke risk (HR, 1.30 [95% CI, 1.15-1.46]). Similarly, abnormal ABI groups were associated with a significant risk for all cause mortality in a severity-dependent manner, with severe PAD conferring the greatest risk (HR, 3.07 [95% CI, 2.88-3.27]). CONCLUSIONS: This study adds to the growing body of evidence that both PAD and PCA are independent risk factors for incident ischemic stroke and all cause mortality. The association of PAD severity and PCA with risk of ischemic stroke may help clinicians with risk stratification and determining treatment intensity.

Discordant Values in Lower Extremity Physiologic Studies Predict Increased Cardiovascular Risk.

Background Ankle-brachial indexes (ABI) are a noninvasive diagnostic tool for peripheral arterial disease and a marker of increased cardiovascular risk. ABI is calculated using the highest systolic blood pressure of the 4 ankle arteries (bilateral dorsalis pedis and posterior tibial). Accordingly, patients may be assigned a normal ABI when the result would be abnormal if calculated using one of the other blood pressure readings. Cardiovascular outcomes for patients with discordant ABIs are undescribed. Methods and Results We performed a retrospective study of patients who underwent ABI measurement for any indication between January 1996 and June 2018. Those with normal ABIs (1.00-1.39) were included. We compared patients with all 4 normal ABIs (calculated using all 4 ankle arteries; n=15 577, median age 64.0 years, 54.4% men) to those with discordant ABIs (at least 1 abnormal ABI ≤0.99; n=2095, median age 66.0 years, 47.8% men). The outcomes assessed were ischemic stroke, myocardial infarction, and all-cause mortality. Compared with patients with concordant normal ABIs, patients with discordant ABIs were older; women; smoked; and had chronic kidney disease, coronary artery disease, diabetes mellitus, chronic obstructive pulmonary disease, hypertension, or prior stroke. Patients with discordant ABIs had a greater risk of myocardial infarction (hazard ratio [HR], 1.31; 95% CI, 1.10-1.56), ischemic stroke (HR, 1.53; 95% CI, 1.37-1.72), and all-cause mortality (HR, 1.27; 95% CI, 1.16-1.39), including after adjustment for baseline comorbidities. Conclusions Discordant ABI results were associated with an increased risk of myocardial infarction, stroke, and all-cause mortality in the studied population. Clinicians should examine ABI calculations using all 4 ankle arteries to better characterize a patient's cardiovascular risk.

Cardiac Troponin T and Right Ventricular Systolic Pressure Predict Cardiovascular and Mortality Risk in Kidney Transplant Candidates.

BACKGROUND: Patients presenting for kidney transplant (KTx) evaluation are subject to high rates of mortality and cardiovascular (CV) events pre- and post-KTx. CV and mortality risk assessment is needed. METHODS: We evaluated cardiac troponin T (cTnT) as a predictor of CV events and mortality in a racially diverse cohort with significant CV disease burden presenting for KTx evaluation. Right ventricular systolic pressure (RVSP) was also assessed in predicting these outcomes. The population consisted of 561 patients presenting for KTx evaluation from 2011 to 2013 at Mayo Clinic, Arizona. A cutoff value for cTnT and RVSP that was most associated with CV events or mortality was derived. Multivariate Cox regression analysis was used to assess cTnT, RVSP, traditional, and other risk factors for the outcomes of interest. RESULTS: Mean age was 53.5 ± 13.7 years and the median follow-up after KTx evaluation was 48.0 months. The cohort was 70.6% (n = 392) White, 11.4% (n = 63) Black, 8.5% (n = 47) Native American, and 3.1% (n = 17) Asian. Preexisting CV disease at the time of evaluation was prevalent in 24.4% (n = 137) of patients. During follow-up, 66.3% (n = 372) received a KTx and 21.9% (n = 123) had a composite event (16.8% death, 6.6 % CV events). It was found that 70.7% (n = 87) of events occurred in patients who were not transplanted; 53.5% (n = 300) had an elevated cTnT (≥0.01 ng/mL, median 0.02 ng/mL) and 84.1% (n = 344) of patients with RVSP data had an elevated RVSP (>25 mm Hg). Time to event analysis identified a cTnT ≥0.036 ng/mL and RVSP ≥31 mm Hg to be best predictive of CV events and mortality. Smoking, CV disease, hypoalbuminemia, RVSP, and cTnT independently predicted CV events and mortality. CONCLUSION: Elevated cTnT and RVSP were independently predictive of CV events and mortality in the cohort. Clinicians should consider the value of RVSP and cTnT as markers of CV risk in KTx evaluation.

Cardiac Troponin T Risk Stratification Model Predicts All-Cause Mortality Following Kidney Transplant.

BACKGROUND: We evaluated the role of increased cardiac troponin T (cTnT), vascular, and cardiac diseases in predicting 5 and 10-year all-cause mortality after kidney transplantation. METHODS: We reviewed a cohort of 764 kidney transplant recipients and analyzed pertinent cardiovascular risk factors at the time of transplant evaluation. Proportional hazards regression analysis with bootstrapping method was utilized to provide a risk stratification score for mortality. RESULTS: Mean age was 58.8 years (SD 12.1) and median follow-up was 7.0 years (range 1 day to 18.0 years). Fifty-four percent of patients (n = 415) had cTnT measured (median 0.02 ng/mL, range 0.01-4.91). Fifty-three percent (n = 407) had vascular disease, 59% (n = 448) had diabetes, and 44% (n = 336) had cardiac disease pre-transplant. Sixty percent (n = 460) required dialysis. Older age, increased cTnT, pre-transplant vascular and cardiac diseases predicted mortality in multivariate analysis. We derived 2 scoring systems with and without cTnT - the ACV and ACTV scores (age, cardiac disease, elevated cTnT, and vascular disease) - as predictors of mortality after kidney transplant. Point assignments were: age 60-69 years (1), age ≥70 years (2), cardiac disease (1), cTnT ≥0.04 ng/mL (1), and vascular disease (1). Both scoring systems significantly predicted mortality. The ACTV score better delineated risk stratification across score levels (0-2, 3-4, and 5 points). CONCLUSIONS: We developed a risk schema predictive of all-cause mortality after kidney transplant in a derivation cohort. The ACTV score, including an elevated cTnT, provided superior prediction compared to a scoring system without cTnT. Further studies to validate these findings are needed.

A Case Report of Cronkhite-Canada Syndrome Complicated by Membranous Nephropathy.

Cronkhite-Canada syndrome (CCS) is a very rare disorder with less than 500 reported cases. It is characterized by extensive gastrointestinal polyposis and ectodermal anomalies including alopecia, cutaneous hyperpigmentation, and onychodystrophy. Only 3 cases of associated kidney disease (membranous nephropathy [MN]) have been reported. A 71-year-old male with CCS was referred for further evaluation of proteinuria. The patient initially presented with abdominal discomfort, weight loss, dysgeusia, skin hyperpigmentation, alopecia, and dystrophic nails. Endoscopic evaluation showed widespread gastrointestinal nodular inflammation and polyps. Histopathology was consistent with CCS. Initial treatment was with prednisone, azathioprine, and ranitidine. He had moderate clinical improvement but developed nephrotic-range proteinuria. Renal biopsy showed MN, and cyclosporine was started. The patient had significant improvement in his CCS manifestations; however, his proteinuria and renal function worsened. Rituximab was added to his regimen of cyclosporine and azathioprine, which resulted in remission of his MN, marked improvement in his polyposis, and near resolution of his cutaneous symptoms. This case represents a unique presentation of CCS associated with MN treated with rituximab. The excellent clinical response observed for both CCS and MN advocates consideration of this treatment, especially for refractory disease.